Components of the Immune System
The immune system is the body’s way of defending itself. It has three levels of defence called the First level, Second level and Third level. They each have different ways of defending the body and combating pathogens and antigens. The First level is known as know specific and includes the skin, mucus, ear wax, hairs and cilia (cilia are small hair like structure that coat the throat), gastric juices, sweat tears and saliva. The first level attempts to stop foreign agents from entering the body in the first place, however if something does enter then the second level immune system takes over. This level uses what is known as cellular meditating, which mean cells are involved. The second level is also classified a non-specific as the macrophages which are often the case engulf all foreign invaders with no preference to what they will engulf, that is left to the third level immune system. The third level immune system is a specific system meaning that only certain cells and sometime chemicals will be called upon to fight off the pathogen or antigen. The third level consists of communication through cells which often starts with a macrophage engulfing a foreign agent and displaying a antigenic fragment for T-helper cells to collect and transport to the lymph node so that either a new plasma B cell can be produced to create antibodies or whether this is an already encounter antigen in which case a memory B cell will divide and one cell of the newly divided memory B cell will become a plasma B cell and produce antibodies, specific to the antigen.